Rotary solenoid



May-11, 1965 G. s. CHERNIAK ROTARY SOLENOID 2 Sheets-Sheet 1 Filed Aug. 14, 1961 NEY.

ATTOR 2 Sheets-Sheet 2 Filed Aug. 14, 1961 INVENTOR: GEORGE S. CHERNIAK BY @MJMM ATTORNEY.

United States Patent 0 3,183,418 ROTARY SQLENOID George S. Cherniak, Eau Gallic, Fla. (522 Andros Lane, Indian Harbour Beach, Fla.) Filed Aug. 14, 1961, Ser. No. 131,189 4 Claims. (Cl. 317-192) This invention relates generally to solenoids and more particularly it is concerned with solenoid operated devices which produce rotational movement.

*Solenoid devices which produce rotational, as distinguished from translational movement, are well kown to those skilled in the art. In one conventional type of rotary solenoid, the armature is linearly movable and the linear movement of the armature is translated into rotary shaft output by some mechanical means. This type of construction lends itself to use with a relatively simple and straightforward electrornagnet configuration.

Most devices of this type produce axial motion of the output shaft as Well as rotary motion This often presents a problem because many applications for rotary solenoids do not admit of axial movement of the output shaft. Also the mechanical translating means, as well as the basic arrangement of the essential elements of such devices introduce a great deal of friction which substantially reduces operating efiiciency.

Other mechanical translating means have been proposed in an attempt to eliminate the above-mentioned limitations. However, these have required relatively complex mechanisms which are correspondingly less reliable in operation and are more costly to manufacture.

A further limitation has been that output shaft rotation is limited to relatively small angles.

It is an object of the present invention, there-fore, to

provide a solenoid operated device which produces only rotary movement of the output shaft.

'Another object of the invention is to provide high operating efiiciency in a device of this character by minimizing the effects of friction.

' Another object of the invention is to provide a device which has few parts and is simple to manufacture.

Still another object is to provide angular output movement of any desired amount.

#A further object of the invention is to provide for a wide choice in the relationship between the output torque and the stroke of the solenoid armature.

The novel features of the invention together with further objects and advantages will become apparent from the following detailed description and the drawings to which it refers. In the drawings:

FIG. 1 is .a sectional view of the rotary solenoid in accordance with the present invention;

FIG. 2 is a section taken on the line 22 of FIG. 1;

FIG. 3 is an exploded view of the ball retainer and armature member;

FIG. 4 is an exploded view of the output shaft memher.

With reference to the drawing, it will be observed that the numeral 11 designates a coil which is suitably insulated and has a pair of leads 12 for connection to a suitable power source. The coil is concentrically located within a cylindrical housing 13 of magnetic material. Coaxial with the coil is a fixed magnetic core 14 that is flanged so as to form a closure at the rearward end of the housing 13-. A fixed pole piece 15 in the form of a disc of magnetic material having an axial bore abuts the forward end of the coil and the peripheral edge thereof engages the inner wall of the housing. Thus the pole piece 15, the housing 13, and the core 14 provide a path of low magnetic reluctance for the flux generated by the coil.

3,183,413 Patented May 11, 1965 Also disposed co-axially within the coil is a hollow cylindrical armature member 16 which is flared radially outwardly toward the front of the housing. As shown, the flare terminates in a cylindrical surface which is provided with symmetrically located grooves 17. The grooves are preferably helicoid in nature but may differ from a true helix according to the specification of torque-stroke relationship which it is desired to implement. The armature member is made of a magnetic material. A cup shaped member 18 surrounds the grooved portion of the armature and extends across the front of the housing. Circular holes 29 are provided in the cylindrical wall of the member 18 adjacent the armature grooves. These serve to retain steel balls 19 which are disposed in a cooperative engagement with the armature grooves,

The output shaft 21 is co-axially located with respect to the armature and is supported at one end by a bearing 22 centrally mounted in the ball retainer member as shown. The inner end of the shaft is provided with a cylindrical enlargement having axial grooves 24. The armature is provided with corresponding grooves 23. Steel balls 25 are disposed in cooperative engagement with the armature grooves 23 and the shaft grooves 24. The balls are retained in the grooves by a snap ring 26 mounted on the shaft immediately adjacent the rearward end of the enlargement and by a helical compression spring 27 slidably mounted on the shaft adjacent the forward end of the enlargement. The compression spring is retained within the armature bore by staking 28 of the metal defining the forward end thereof. Finally, a second snap ring 29 is secured to the shaft external and immediately adjacent to the bearing 22.

in operation, with the solenoid coil de-energized the armature is positioned as shown in FIG. 1. When current is caused to how through the coil 11, there is produced an electromagnetic force which acts on the armature in an axial direction. This causes the armature to be retracted into the coil, that is to move towards the right of FIG. 1 against the force of the compression spring 27 until it comes in contact with the core 14.

T he spring, in turn, acts on the shaft enlargement urging it toward the right of FIG. 1, and causing snap ring 29 to bear against the external surface of bearing 22. The spring pressure on the shaft enlargement and the resulting pressure of the snap ring against the bearing surface effectively prevent axial motion of the shaft, in either direction.

During the axial movement of the armature, the balls 19 exert a tangential reactive force against the sides of the corresponding grooves 17 causing the armature to rotate as it moves axially. By means of the balls 25 in the grooves 24 and 23, this rotational movement of the armature is transmitted to the output shaft 21 but the axial movement is not transmitted due to the free play in the axial direction between the armature and the output member aflorded by the balls 25. Conversely, when the current in the solenoid coil is interrupted, the spring 27 acts to move the armature outwardly and as it moves, the corresponding opposed reactive forces of the balls on the sides of the grooves cause the armature to rotate in the opposite direction. As before, rotational movement of the armature is transmitted .to the output shaft to return it to its initial angular position without producing any axial movement of the shaft. Torque is dependent upon the diameter of the grooved portion of the armature and the helix angle of the grooves. The larger is the diameter and helix angle the greater will be the torque.

Although the invention has been described in terms of a single preferred construction, it will be appreciated by those skilled in the art that various modified and alternative constructions Within the spirit and scope of the invention are possible. For example the grooves in the outer surface of the armature member may differ in shape area ire from a true helix if it is desired to obtain a diiterent relationship between the axial motion of the armature and the output member rotation. Also, it Will be appreciated that a greater number of mating axial grooves can be provided in the armature and the output member. There-fore, the invention should not be deemed tobe I limited to the details of What has been described herein tional movement thereof, camming means acting upon a surface portion of said armature member extending generally in the direction of its translational movement to impart rotational movement as said member moves in translation, and an output member mounted for rotational movement, said armature member being coupled to said output member for rotation therewith but being free to move intranslation with respect thereto.

2. A rotary solenoid including a generally cylindrical armature member, a solenoid coil disposed concentrically about a portion of said armature member to create a force tending to produce axial movement thereof, a housing surrounding said coil and said armature member, a bearing'ball, a retainer for said ball mounted in a fixed position Within said housing, said armature member being provided with a helical groove extending along the surface of a longitudinal portion thereof and said ball being disposed in cooperative engagement with the walls of said groove to impart rotational movement to said armature member as said member undergoes axial movement, and an output member concentric with said armature member and having one of its ends projecting from said housing, said armature member being coupled to said output member for rotation therewith but being free to move in translation with respect thereto.

3. A rotary solenoid including a generally cylindrical armature member, a solenoid coil to create a'force tending to produce axial movement thereof, a housing surrounding said coil and said armature member, a bearing ball, a retainer for said ball mounted in a fixed position Within said housing, said armature member being pro- 45 'vided with a helical groove extending along the surface a of a longitudinal portion thereof and said ball being disposed in cooperative engagement with the Walls of said groove to impart rotational movement to said armature member as said member undergoes axial movement, an output member mounted for rotation with one of its ends projecting from said housing, said output member and said armature member being provided with mating grooves extending axially thereof, and a plurality of bearing balls disposed in the passages defined by said grooves to produce only rotational movement of said output member when said armature member undergoes combined rotational and axial movement.

4. -A rotary solenoid comprising a hollow cylindrical armature member, a solenoid coil disposed concentrically about a portion "of said armature member to create a force tending to produce axial movement thereof, a housing disposed conwntrically about said coil, said armature member being movable into and out of contact with one end of said housing, a bearing ball, a retainer for said ball fixedly mounted in said housing axially adjacent to said coil, said armature member being provided with a helical groove extending along the surface of a longitudinal portion thereof and said ball being disposed in cooperative engagement with the Walls of said helical groove to impart rotational movement to said armature member as-it undergoes axial movement, an output memher having one of its ends projecting from the forward end of said housing, said armature and output members being provided with mating axial grooves in their inner and outer walls, respectively, a plurality of bearing balls disposed in the passages defined by said axial grooves to produce only rotational movement of said output memher when said armature member undergoes combined rotational and axial movement, and acompression spring mounted on said output member to urge said armature member out of contact with said one end of the housing.

References Cited by the Examiner UNITED STATES PATENTS 2,828,636 4/58 Hall 200-411 2,866,910 12/58 Bentley. 7

2,972,467 2/61 Gilman 317-192 3,027,772 4/62 Smith 3 l7192 *JGHN F. BURNS, Primary Examiner. 

1. A ROTARY SOLENOID COMPRISING AN ARMATURE MEMBER MOUNTED FOR COMBINED TRANSLATIONAL AND ROTATIONAL MOVEMENT, AN ELECTROMAGNET TO CREATE A LINEARLY ACTING FORCE ON SAID ARMATURE MEMBER TENDING TO PRODUCE TRANSLATIONAL MOVEMENT THEREOF, CAMMING MEANS ACTING UPON A SURFACE PORTION OF SAID ARMATURE MEMBER EXTENDING GENERALLY IN THE DIRECTION OF ITS TRANSLATION MOVEMENT TO IMPART ROTATIONAL MOVEMENT AS SAID MEMBER MOVES IN TRANSLATION, AND AN OUTPUT MEMBER MOUNTED FOR ROTATIONAL MOVEMENT, SAID ARMATURE MEMBER BEING COUPLED TO SAID OUTPUT MEMBER FOR ROTATION THEREWITH BUT BEING FREE TO MOVE IN TRANSLATION WITH RESPECT THERETO. 